docs: def update_parser(self, parser):
          """Update config dictionary with declared arguments in an argparse.parser
          New variables will be created, and existing ones overridden.
  
          Args:
              parser (argparse.ArgumentParser): parser to read variables from
  
          """
  
          self._parser = parser
          ini_str = argparse_to_ini(parser)
          configp = configparser.ConfigParser(allow_no_value=True)
          configp.read_dict(self._config)
          configp.read_string(ini_str)
          self._config.update(
              {s: dict(configp.items(s))
               for s in configp.sections()}
          )